less weight = less load = slower spool up times. This is why you build boost easier in 5th, and much slower in 1st. If you can remove a very significant amount of weight, it can affect your tune as most tuners dont tune for every psi at every RPM point. It really depends on how much weight and how shitty of a tune it has.

 

Benefits of lighter weight far out weight 100rpm loss in spool.

 

so with that thought, it should be really easy to blow off when you're not in gear, right?
so i must be revving my engine wrong, cuz when i'm not in gear, its damn near impossible to blowoff....


maybe you're confusing the amount of time and "work" involved to get to the higher RPMs in which your turbo is spooled.
You're turbo is gonna spool at the same(ish) RPM regardless. When you lower the rotating mass, the engine can get to those higher RPMs faster.
So its kinda like the turbo spools sooner....

 

i forgot to take that into account. if you have a really good tune, then it shouldn't really matter, but if you just have a "get it running" tune, then yeah, you'll notice a big difference.
This is more of an issue with boosted set ups. From what I can tell from previous threads, speedcat is building one hell of a NA set up.

 

dee dee dee no its not easy to blow off without being in gear hence no load. thats why I said the more load the harder the turbo works. the turbo is not gonna spool the same. I have 200+ passes on a 3,000 lb. inertia wheel dyno jet. on the dyno the 35r cracks the wastegate @ 4,800 rpms. on the street its 4,600 rpms. the 3,000 lb inertia wheel doesnt simulate the exact load that the s13 actually has. less rotating mass helps spool up. if it didnt I would have 26" spinners with Mickey's instead of 15" welds.

 

thanks guys. Norachel, that makes good sence about less weight less load, quicker sool time reaches higher rpms quicker. What im figuring out is between NA and turbo, advan and disadvan of both. Im also trying to figure out if I want to put this and that to make hp or only this and that and reduce some weight to even things out. u guys are helping alot tho. Sorry those are not my advans, they are 5 lug 9 inch lip metallic blue tho. this guys shop I used to hang out at was building one hell of a 240. lambo doors, green and black bride seats, yellow paint with green pearl overlay that gave a sherbert effect inthe sunset. Other car was being built there was a s13 with hatch turned into a trunk. It was white with the same green pearal overlay, on some gold volks. U probly will see the cars in some tunner mags, I dunno when tho.The one guy named trey that owns the yellow 240 dicked me out of some serious money so It fucked up the money for my project. I traded him my busted gst for a s13 just so it would get me to work, shit spun a bearing 2 weeks later. Im on a revenge build, dont care how long it takes to do. shoulda took those advans, lookin for some to powder coat and chrome lip. I still talk to the other guy with the white s13 truck. Havent asked him how far along he is in a while. the guy trey screwed him outta parts and shit for his car so he got a little behind. they both plan on drifting with ther cars.

 

An inertial dyno will never simulate real world load, I dont see why you felt the need to to write half a paragraph to state the obvious. I do not believe you are TOTALLY clueless, as your example just reinforced what I said. I believe you just have a problem putting your thoughts / concepts into words.